Exodus 13:9-16

9And it shall be for a sign unto thee upon thine hand, and for a memorial between thine eyes, that the law of the LORD may be in thy mouth: for with a strong hand hath the LORD brought thee out of Egypt.

10Thou shalt therefore keep this ordinance in its season from year to year.

11And it shall be when the LORD shall bring thee into the land of the Canaanite, as he sware unto thee and to thy fathers, and shall give it thee,

12that thou shalt set apart unto the LORD all that openeth the womb, and every firstling which thou hast that cometh of a beast; the males shall be the LORD’S.

13And every firstling of an ass thou shalt redeem with a lamb; and if thou wilt not redeem it, then thou shalt break its neck: and all the firstborn of man among thy sons shalt thou redeem.

14And it shall be when thy son asketh thee in time to come, saying, What is this? that thou shalt say unto him, By strength of hand the LORD brought us out from Egypt, from the house of bondage:

15and it came to pass, when Pharaoh would hardly let us go, that the LORD slew all the firstborn in the land of Egypt, both the firstborn of man, and the firstborn of beast: therefore I sacrifice to the LORD all that openeth the womb, being males; but all the firstborn of my sons I redeem.

16And it shall be for a sign upon thine hand, and for frontlets between thine eyes: for by strength of hand the LORD brought us forth out of Egypt.